clothoidLaneBoundary
Clothoid-shaped lane boundary model
Description
A clothoidLaneBoundary object contains
information about a clothoid-shaped lane boundary model. A
clothoid is a type of curve whose rate of change of curvature
varies linearly with distance.
Creation
Description
bdry = clothoidLaneBoundarybdry with default property
values.
bdry = clothoidLaneBoundary(Name,Value)clothoidLaneBoundary('BoundaryType','Solid') creates a
clothoid lane boundary model with solid lane boundaries. Enclose each property
name in quotes.
Properties
Curvature — Lane boundary curvature
0 (default) | real scalar
Lane boundary curvature, specified as a real scalar. This property represents the rate of change of lane boundary direction with respect to distance. Units are in degrees per meter.
Example: -1.0
Data Types: single | double
CurvatureDerivative — Derivative of lane boundary curvature
0 (default) | real scalar
Derivative of lane boundary curvature, specified as a real scalar. This property represents the rate of change of lane curvature with respect to distance. Units are in degrees per meter squared.
Example: -0.01
Data Types: single | double
CurveLength — Length of lane boundary along road
0 (default) | nonnegative real scalar
Length of the lane boundary along the road, specified as a nonnegative real scalar. Units are in meters.
Example: 25
Data Types: single | double
HeadingAngle — Initial lane boundary heading
0 (default) | real scalar
Initial lane boundary heading, specified as a real scalar. The heading angle of the lane boundary is relative to the heading of the ego vehicle. Units are in degrees.
Example: 10
Data Types: single | double
LateralOffset — Distance of lane boundary
0 (default) | real scalar
Distance of the lane boundary from the ego vehicle position, specified as a real scalar. A lane boundary offset to the left of the ego vehicle is positive. An offset to the right of the ego vehicle is negative. Units are in meters.
Example: -1.2
Data Types: single | double
BoundaryType — Type of lane boundary marking
'Unmarked' (default) | 'Solid' | 'Dashed' | 'DoubleSolid' | 'DoubleDashed' | 'SolidDashed' | 'DashedSolid'
Type of lane boundary marking, specified as one of these values.
'Unmarked' | 'Solid' | 'Dashed' | 'DoubleSolid' | 'DoubleDashed' | 'SolidDashed' | 'DashedSolid' |
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No lane marking | Solid line | Dashed line | Two solid lines | Two dashed lines | Solid line on left, dashed line on right | Dashed line on left, solid line on right |
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Strength — Visibility of lane boundary marking
1 (default) | real scalar in the range [0, 1]
Visibility of lane marking, specified as a real scalar in the range [0,
1]. A value of 0 corresponds to a marking that is not
visible. A value of 1 corresponds to a marking that is
completely visible. For a double lane marking, the same strength is used for
both lines.
Example: 0.9
Data Types: single | double
XExtent — Extent of lane boundary marking along X-axis
[0 Inf] (default) | real-valued vector of the form
[Xmin
Xmax]
Extent of the lane boundary marking along the X-axis, specified as a real-valued vector of the form [Xmin Xmax]. Units are in meters. The X-axis runs vertically and is positive in the forward direction of the ego vehicle.
Example: [0 100]
Data Types: single | double
Width — Width of lane boundary marking
0 (default) | nonnegative real scalar
Width of lane boundary marking, specified as a nonnegative real scalar. For a double lane marking, this value applies to the width of each lane marking and to the distance between those markings. Units are in meters.
Example: 0.15
Data Types: single | double
Object Functions
computeBoundaryModel | Compute lane boundary points from clothoid lane boundary model |
Examples
Create Clothoid Lane Boundaries
Create clothoid curves to represent left and right lane boundaries. Then, plot the curves.
Create the left boundary.
lb = clothoidLaneBoundary('BoundaryType','Solid', ... 'Strength',1,'Width',0.2,'CurveLength',40, ... 'Curvature',-0.8,'LateralOffset',2,'HeadingAngle',10);
Create the right boundary with almost identical properties.
rb = lb; rb.LateralOffset = -2;
Create a bird's-eye plot. Then, create the lane boundary plotters and plot the boundaries.
bep = birdsEyePlot('XLimits',[0 50],'YLimits',[-10 10]); lbPlotter = laneBoundaryPlotter(bep,'DisplayName','Left-lane boundary','Color','r'); rbPlotter = laneBoundaryPlotter(bep,'DisplayName','Right-lane boundary','Color','g'); plotLaneBoundary(lbPlotter,lb) plotLaneBoundary(rbPlotter,rb); grid hold on
Plot the coordinates of selected points along the boundaries.
x = 0:5:50; yl = computeBoundaryModel(lb,x); yr = computeBoundaryModel(rb,x); plot(x,yl,'ro') plot(x,yr,'go') hold off
